Hydraulic forming machine



March 20, 1951 A. E. CALDWELL 2,545,570

HYDRAULIC FORMING MACHINE Filed Jan. 10, 1945 5 Sheets-Sheet 1 454? 1 id! well y March 20, 1951 A. E. CALDWELL HYDRAULIC FOBMING MACHINE 5 Sheets-Sheet 2 Filed Jan. 10, 1945 5 Sheets-Sheet 3 Filed Jan. 10, 1945 March 20, 1951 A. E. CALDWELL HYDRAULIC FORMING MACHINE 5 Sheets-Sheet 4 Filed Jan. 10, 1945 zlorney March 20, 1951 A. E. CALDWELL HYDRAULIC FORMING MACHINE 5 Sheets-Sheet 5 Filed Jan. 10, 1945 Patented Mar. 20, 1951 HYDRAULIC FORMING MACHINE Albert; Earl Caldwell Chicago, Ill., assignor to Raymond T; Moloney, Chicago, Ill.

Application January-1'0, 1945., Serial No. 572,177.

1 Claim., (Cl. 113-45) This invention pertains to the metal-workin arts, particularly dieestamping, punching, and forming apparatus and methods;

It, is. aprincipal object of the inventionto provide. a mechano-hydra-ulic forming machine adapted tobe. used in conjunction with an -ordinary punch press and capable of automatica-lly performing a sequence of punching, stampins... and formin operations of predetermined character; which. would otherwise have to be performed manually or by relatively complicat ed and expensive machines and processes in the knownart.

More particularly; the invention provides. a forming machinev consisting; of a plurality of co.- operating mechanical: and. hydraulic diet and fluid-displacement means, and automatic flowcontrol means therefor, actingto punch metal from stock, pre-form. the; punching. by. pistondisplaced die means, additionally form, the resulting stamping by direct. hydraulic displace-. ment of the stamping;- metal, and performing; still further punching operations on the object.

thus formed by direct: fluid displacement, all in rapid succession and by a relatively small, uni.- tary device adapted; to. receive its. principal. operating power from apunch press.

Viewed from another a pect, the invention. providesa method and unitary mechanism for effectuating the method.- which consists of a plurality of pistons, cooperatin die means, and a closed. system of. fluid controlvalves and bypassing connectionsand means coacting to cause,v

a predetermined sequence. of. operations. upon metal stock. to form and. punch Cup.-1ike0bjectS..

Detailed aspects. of novelty. in. the device re.- late to the construction and. operation of certain compound. piston. means; to. the utilization of.

bodily displacement, and. fluid displacement of. metal stock. in. a certain. order. to permit, multiple forming. operations. in av single. die; to certain. fiuidy-passing, means; for controlling the. sequence of forming operations; to the utiliza-- tion. ofv the metal tock itself for gauging purposes in the. automatic. operation. of the device;

and to specific details of the. construction. and. operation. of the. means, tor. carrying out the. method disclosed, all" of which- Will appear. as.

Fig. 2 is an enlarged; sectional fragmentv through the main. die. and. die piston, with. the.

2 die piston fully advanced in a pre-forming: op-- eration;v

Fig. 3 is. adetail similar to Fig. 2, showing; the.. die. piston partly retracted preparatory to further forming operations;

Fig. 4' is, a vertical. median section through: the, forming pistons of Fig. 1;

Fig. 5 is an elevational. view along lines of Fig.v 1,, looking atthe female die unit;

Fig. 6 is a. vertical section along lines 6.--6 of- Eig. 4, with parts in elevation, lookingat the: outer end of themale'dieaunit;

Fig. 7 is a vertical section anlong lines I -1 of" Fig. 4*, looking into themale die unit;

Fig, 8 is an enlarged. sectional fragment through the male and female dies, similar to Figs, 2 and 3, but showing themetal. stock punched and gauged, readyfor pre-forming;

Fig. 9; is asectional detail through the split female die, alonglines 99- oi Fig. 4;

Fig. 10 is a sectional operating diagram.

The invention is best understood by way of a. generalized introductory explanation of its operation in view of Fig. 10-, wherein a male die tion E, carried on piston means-F moving in..cyl-- inder Within die unit. E is the female die; proper,

' E (in the shape of a threaded cylinder, for ex,-

ample), and within die unit A is a male die A carried on forming piston A which works inside of piston B, and which. is also an extension of piston C.

Also part: of. female die section E is a stock bed E with stock' guides E and pro-forming passage E A- fluid: passage D communicates from a working: or pressure cylinder F directly to by-pass,

ductv D? in cylinder D; this duct opens at D? behind main piston C; and at D at a point'alons.

the; path of travelof. piston C. Duct D leads from: apoint; of. normal closure by piston 2B.into female die-closing piston cylinder G via ducts For initialoperation; (Fig. 10.) raising-of piston- B-drawsoilfromsump H through duct; H, valve (aswell. as residual oil, after the device has been. operating; from other parts, as will appear hereinafterl and upon: the compression strokes of piston P all valves are closed, so that oilthrough Joy-pass port 12) drives die piston A forward, (to. the, left).- intov thenormally extended conditionshown in, Fig. 10. by action of oil, entering chamber C through passage C Also, oil entering at D drives main piston C and its splitpiston section B forward (to the left) as a unit by reason of the fact that oil is trapped in the chamber between these two main pistons B and C.

However, as soon as piston B opens port D the oil coupling between B and C by-passes to cylinder G via ducts G, G and urges forward (to the right) the female die-closing piston F so that the female die section will be in the condition shown in Fig. 10.

Meanwhile, metal stock will have been fed by any suitable means into the stock and punching bed guides E and the aforesaid initial movement of piston B (until port D is opened) causes the male punching die section J to engage this stock and punch out the desired piece .of stock. During this operation, piston C continues to move forward after piston B has stopped, in consequence of which piston A drives its male forming die portion A into the metal punching carrying the latter into the forming sections E, E, thus forming up a cup-shaped article.

When piston C has moved far enough to register by-pass duct C with port D movement of C stops, because the oil under pressure now is by-passed through duct A inside piston A and the by-passed oil escapes from around a spe- Qialrubber piston ring or sk rt (not seen in Fig. see Fig. 3 at A later to be described, and into the now preformed stamping, with the result that the forming piston A now backs out of the female die part E, but remains sealed, by means of said special rubber skirt, in die part E while oil continues to escape into the cup-shaped s amp The aforesaid backing-out of piston A is made possible by registration of duct C with duct C permitting the oil in chamber C to expand in between main pistons B and C and through port D and valve G into the sump.

- Fluid pressur cont nues to be exerted upon the interior of the preformed cup through duct A in consequence of which screw threads are formed in this cup by forcing of the metalwall stock thereof into the threading cut into the female die; such formation of the threads take place while the male die part A is receding, and the recessive movement of A, A sto s before the oil seal by the rubber sk rt is broken, so that as the pressure continues, still further forming operation are effected, as for examp e the punching out of stock from the bottom of the cup into the cavity of a small backing-up piston K, to make a desired hole in the article.

' At this juncture, the compression stroke of the working piston P is completed. By retraction of this p ston, a suction is created at the check valve A in the nose of the male die, via ducts A C. D withdrawing the oil from the completed stamping or cup, and when the distributed pressures in the system are relieved, certain spring means, including spring L, plus suction at D retracts the compound piston means A, B, C. valve D opening to permit refilling of the chamber between B and C, since D is quickly closed and asuction is created between B and C.

As a further result of raising piston P, oil is withdrawn from cylinder G, retracting piston F and the female die unit. so that the latter is caused to open and discharge the finished article.

Detailed construction and operation Referring to Fig. 1, a view looking down on the device, there is provided a heavy base casting 20,

upon which is bolted, as at 2|, the cylinder 22 for the working piston P, consisting of the piston proper, 23, and drive rod 24, secured by plate 25 bolted to the cylinder (see Fig. 5). Reservoir H, and valves H G D heretofore described, are threaded into this base plate, as in Fig. 1, and the ducts, such as D, G, G H, H are conveniently drilled into said base plate, as for example duct D or G in Figs. 4 and 5.

Continuing with Fig. 1, the cylinder jacket D is mounted in a casting 2'5, bolted as at 28 (Figs. 4 and 6) an end plate 29 is bolted at 3D to casting 21, and as at 3! to jacket D.

End plate 29 has a sleeve 32 in which piston rod 33 works, this rod being oil-sealed and threadably rigid, as at 34, with piston C, and terminating in a flanged head 35, against which bears spring L. A cap casting 36 is bolted as at 31 to plate At the opposite or inner end of the foregoing compound piston unit (Fig. 1), there is provided a recessed head plate 40 having a central passage which fits over the reduced end B of piston B, and also having diametrically opposite wings with passages in which are slide bearings 4i riding on rods 42 respectively seated at one end in bosses 21a of the casting 21, and at their opposite ends in flange portions 5| of the mounting :for"

cylinder G. Nuts 43 secure rods 42. Com'pres' sion springs 4 on'rods 42-between head plate- 40 and stock bedE normally keep the male unit A opened,toward th e right, from bed E A male blanking die 46 (the die proper being ton C. The control ports inclusively indicated by characters 0' etc. and D etc., heretofore referred to, are seen in part in Fig. 4.

The female die piston cylinder G (Fig. 1) is shrunk into a shell 56 having flange portions 5 through which the guide rods 42 project for engagement with retaining nuts 43, the shell being bolted to base 20 as at 52 Fig. 4.

Piston F for the female die (Fig. 1) has a flanged end 54 bolted as at 55 in the recess of a carrier casting 55 having slide bearing sleeves 51 in o posite flange portions 58 of the casting, said sleeves sliding on rods 42, and the piston and carrier part normally being urged to the left by com ression springs 59 on rods 42, acting against said flange portions and against the stationary guide plate E to open the split female die.

As vie ed in Fig. 1, stock guide plate is" has partial rigidifying support from rods 42, and the plate is also bolted as at 60 to the base plate, Figs.

4 and 5.

Referring particularly to Fig. 5, guide plateE The main female die is of the split variety, consisting (Fig. 9) of a carrying block 65,-which is part of carrier casting 56 on piston means F,

having pairs of tapered keying bosses pro-- jected horizontally therefrom, split die-holder blocks 6! and 68,,each having correspondingly tapered keyways 69 interfitting bosses 66, being adapted to spllt cr' -separ teralong a verti lls finder: urs se Qt; rings; L ar therein. The ale-diaman e. ilsswis sel g a line conforming to line H1: this does not appear in Fig. 9:, but is seen in Figs.- I and 2, for-Iexam-.

ple, one. each of. these main d-iesections. bein fitted into} one. of the carrier. block sections 61 or. 8.8.

Carrierbl'ock sections 611 and: 68. have conical nose. portions 13. closably fitting into comple mentary formations. in seat. 14'. on guide plate. E when the femaledie. section is urged forward by pistonF; but when the-lattenpiston is retracted, springs- H. spread apart the. die sections 61, 68 (Figs. 13 and 9la1ong-line10'; so that thcformed articlemaydrop out and-passdown through dis charge opening 15 inthebase plate 20.

Additional punching, means, includes j. a cavity 16 in sealing plunger Tl (Figs, 1 and 8) threade l secured as at 18 in the carrier casting shell- 55,' this cavity 76 leads into the bottomf the cavity of die E andcontains a punch or backing plunger 19 (also indicated at K, Fig. l) on rod 80 slidable in plunger 11, a spring 8|; normally urging the backing plunger into register with the bottom of the die cavity asin Fig. 8.

In the operation of the device, referring again to Fig. 10, piston F is retracted into its cylinder G at the beginning of the cycle, it being understood that piston F is shown otherwise, that is, in advanced position in Fig. for illustrative purposes; and the male die unit A is,' also withdrawn from plate E as actually shown in Fig. 10.

By retraction of the working piston P, negative pressure is created throughoutjhe system, and valves D G and H open as necessary, depending upon the actual 'distribution'iof oil in the several branches, inclusive of losses in E, and accordingly, the die-opening pistonF will be retractedfrom the position shown in Fig. 10, While the male compound-piston unit Awill be restored to the condition shown in Fig. 10, filling the cavity between pistons B and C- with oil via duct D With the retraction of F, the female die sections 61, 68, E open by action of springs N (Fig. 9) dropping out any previously formed article.

Upon descent of the working piston P, valves D G H are closed, and a small quantity of oil enters chamber C through D D and C causing piston part C to be driven forward to the normal condition of Fig. 10, whereupon oil then enters through D behind piston C and drives the entire compound piston assembly forward, since oil is trapped between B and C, and in chamber C Meanwhile, metal stock will have been fed by any suitable means, not shown .(usually part of the punch press with which the device is intended to be used) into stock guides 6! in plate E As soon as piston B passes and opens port D the trapped oil between B and C passes via duct G -G' into the female die cylinder G, thus driving the entire female die assembly E back toward the stock guide E again closing the female die blocks 61, 68 through wedge action of conicalgnose parts 13 in 14 (Fig.1) and similar wedging; action of tapered bosses. .66 in slots 69, so that the female die is conditioned for reception of the blank, as in Fig. 10.

Meanwhile, as in Fig. 8, the male section continues' to advance until the blanking die J or 4B is driven into the stock shearingofi the blank 91'.

A hi junct re. an imn r m zeeusins entice. occursthrough theformation of themale blank ing die. 46 with. accuratelyrecessed portion-s1 45X? (Fig. 8) adapted to bear against-a substantial: area. of the stock strip 90, wherebyitheadvance; of the blankingdie part J is, limited topreventdeforming. or crushing of the blank owing to. probable variations in the: thickness of the stock. Thus, theremnant of the blanked stock is held andautilized as a gauge meansby providingi augev surfaceson both the. malev and female blanking and guide parts.

Continuing with the. operation of thedevice, the piston C will. by now have. advanced'theima-in male die A fully into the metal blank, as in Fig. 2, at which time, control ports C, D (Fig. 10) will be in register, thus arresting further advance ofpiston C and by-passing-the oil into-duct A3 within the backing-offpiston- A Also, ports C C will. be in register permitting this piston A to. backofl, since oilfrom; chamber C ean nowescape via C and C :and:D 'to line G valve G =and thence into sump H. The oil. by-passedw through. A is permitted to escape. through a small duct A in the head A of the male die A and thence around the edge of the rubber ring or skirt A into the cavity of the now partly formed-up article in E, piston A backing off for this purpose as oil leaves chamber C until the head of the male die occupies the position shown in Fig. 3.

In Fig. 2 it will be observed that the now formed blank SIX is cup-shaped with its rim parts 9IY projecting beyond an undercut E in the plate E, but that the side walls of the cup are not yet extruded into the threading cavities E of the female die.

As the male die backs oh, the oil under pressure from duct A forces the metal stock into thread formations E forming threads 92 in the cup, and at the end of travel, rim parts 9lY are sheared off by pressure of the oil, as in Fig. 3; however, the oil still remains sealed in by action of the rubber skirt A and continued pressure of the oil punches out a hole 93 against the backing plunger K or 19, thus completing the forming operations upon the illustrative cup article.

By again retracting the working piston P, the sensitive ball valve A will open and the small quantity of oil in the female die part E will at once be drawn back into passages A D. Almost simultaneously piston B will be restored by action of springs 44, closing port D whereupon valve D will open and permit retraction of piston C and withdrawal of the oil therebehind from port D since oil is replacing the vacuum between B and C by opening of valve D Moreover, piston F will also be retracted, opening the female die to discharge the completed article through passage 15.

It will occur to those skilled in the art that changes in various structural and functional details may be made in the illustrative embodiment described without departing from the spirit of the invention, and that the device may be adapted to form articles of character diifering from that specified, by reason of which it is the intention to include within the scope of the invention all such changes and adaptations as shall fairly come within the appended claim.

I claim: 1

In a hydraulic forming machine, compound blanking and forming dies, hydraulic means including compound piston means comprising a unit for actuating certain of said dies and including a first piston movable to effect coaction of said blanking dies, a second piston'and fluid means coupling the same for predetermined movement to move said first piston for blanking movement as aforesaid, a third piston moved by said second piston into a blank following blanking movement as aforesaid to form up said blank, by-passing port means controlled by movement of said second piston after forming said blank to inject fluid under pressure into said formed blank, fluid means coupling said second and third pistons for'iorming operation by the third piston as aforesaid, by-pass port means controlled by movement of said second piston after forming said blank to uncouple said second and third pistons, said third piston partially Withdrawing from said formed blank by action of fluid by-passed by said first-mentioned by-pass port means to effect said injection, said injection being under pressure to efiect further forming operations on said formed blank, and means operating responsive to negative pressure in said hydraulic means for withdrawing said injected fluid and restoring said dies to an initial condition.

. ALBERT EARL CALDWELL.

'REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 447,265 Wilmot Feb. 24, 1891 506,247 Moorfield Oct. 10, 1893 1,199,414 Pomeroy Sept. 26, 1916 1,690,398 Bollinger Nov. 6, 1928 1,970,999 Ferris Aug. 21, 1934 2,082,199 Dake June 1, 1937 2,162,164 Febrey June 13, 1939 2,298,051 Gordon Oct. 6, 1942 2,341,002 Vollrath Feb. 8, 1944 2,382,046 Flowers Aug. 14, 1945 2,397,106 Haller Mar. 26, 1946 2,407,855 Stephens Sept. 1'7, 1946 FOREIGN PATENTS Number Country Date 5,112 Great Britain of 1887 480,593 Germany of 1929 

